public void Can_add_one_node()
{
// Arrange
BinarySearchTree <int> testTree = new BinarySearchTree <int>();
int expected = 5;
// Act
testTree.Add(5);
// Assert
Assert.Equal(expected, testTree.Root.Value);
}
public static void Add_MultipleKeys_FormsCorrectBST()
{
var tree = new BinarySearchTree <int>();
tree.Add(5);
Assert.AreEqual(1, tree.Count);
tree.Add(3);
Assert.AreEqual(2, tree.Count);
tree.Add(4);
Assert.AreEqual(3, tree.Count);
tree.Add(2);
Assert.AreEqual(4, tree.Count);
var rootNode = tree.Search(5);
Assert.AreEqual(5, rootNode !.Key);
Assert.AreEqual(3, rootNode !.Left !.Key);
Assert.IsNull(rootNode !.Right);
var threeNode = tree.Search(3);
Assert.AreEqual(3, threeNode !.Key);
Assert.AreEqual(2, threeNode !.Left !.Key);
Assert.AreEqual(4, threeNode !.Right !.Key);
var twoNode = tree.Search(2);
Assert.IsNull(twoNode !.Left);
Assert.IsNull(twoNode !.Right);
var fourNode = tree.Search(4);
Assert.IsNull(fourNode !.Left);
Assert.IsNull(fourNode !.Right);
}
public void RedViolationTest_RedUncle_2()
{
ITree <int> tree = new BinarySearchTree <int>();
tree.Add(5);
tree.Add(3);
tree.Add(6);
IBinarySearchTreeNode <int> rootNode = (IBinarySearchTreeNode <int>)tree.Root;
Assert.True(rootNode.IsBlack);
Assert.False(rootNode.Left.IsBlack);
Assert.False(rootNode.Right.IsBlack);
tree.Add(4);
Assert.Equal(4, tree.Count);
Assert.Equal(5, rootNode.Value);
Assert.Equal(3, rootNode.Left.Value);
Assert.Equal(6, rootNode.Right.Value);
Assert.Equal(4, rootNode.Left.Right.Value);
Assert.Null(rootNode.Left.Left);
Assert.Null(rootNode.Left.Right.Left);
Assert.Null(rootNode.Left.Right.Right);
Assert.Null(rootNode.Right.Left);
Assert.Null(rootNode.Right.Right);
Assert.Same(rootNode, rootNode.Left.Parent);
Assert.Same(rootNode, rootNode.Right.Parent);
Assert.Same(rootNode.Left, rootNode.Left.Right.Parent);
Assert.True(rootNode.IsBlack);
Assert.True(rootNode.Left.IsBlack);
Assert.True(rootNode.Right.IsBlack);
Assert.False(rootNode.Left.Right.IsBlack);
}
public void AddFirstNodeTest()
{
ITree <int> tree = new BinarySearchTree <int>();
tree.Add(1);
Assert.Equal(1, tree.Count);
Assert.Equal(1, tree.Root.Value);
IBinarySearchTreeNode <int> rootNode = (IBinarySearchTreeNode <int>)tree.Root;
Assert.True(rootNode.IsBlack);
Assert.Null(rootNode.Left);
Assert.Null(rootNode.Right);
}
public static void Remove_RemoveRoot_CorrectlyRemovesRoot()
{
var tree = new BinarySearchTree <int>();
tree.Add(5);
tree.Remove(5);
Assert.AreEqual(0, tree.Count);
Assert.IsNull(tree.Search(5));
tree.AddRange(new List <int> {
5, 4, 6
});
tree.Remove(5);
Assert.AreEqual(2, tree.Count);
Assert.IsNull(tree.Search(5));
Assert.IsNotNull(tree.Search(4));
Assert.IsNotNull(tree.Search(6));
Assert.AreEqual(6, tree.Search(4) !.Right !.Key);
}
public void Remove_ForNotEmptyTree_Works()
{
//arrange
var bst = new BinarySearchTree <int>();
bst.Add(7);
bst.Add(2);
bst.Add(12);
bst.Add(11);
bst.Add(1);
bst.Add(6);
//act
bst.Remove(7);
//assert
bst.RootNode.Should().NotBeNull();
bst.RootNode.Left.Should().NotBeNull();
bst.RootNode.Right.Should().NotBeNull();
bst.NodesCount.Should().Be(5);
}
public void Can_preorder_big_traverse()
{
// Arrange
BinarySearchTree <int> testTree = new BinarySearchTree <int>();
testTree.Add(5);
testTree.Add(9);
testTree.Add(1);
testTree.Add(8);
testTree.Add(12);
testTree.Add(2);
IEnumerable <int> expected = new int[] { 5, 1, 2, 9, 8, 12 };
// Act
IEnumerable <int> actual = testTree.PreOrder(testTree.ReturnRoot());
// Assert
Assert.Equal(expected, actual);
}